The instant invention relates to the field of spot and stain removers for removing blood and organic stains. These blood and organic stain remover compositions contain at least two different types of enzymes and are stable with time as evidenced by sustained enzyme activity. The inventive spot and stain removers find use in medical offices, hospitals, and the like.
Blood and other organic stains such as for example urine, feces, vomit and the like, are notoriously difficult to remove from fabrics, such as for example clothing, and from hard surfaces, such as for example hardwood floors, cabinet counters, and dental instruments. Pre-spotting prior to the laundering of a garment is typically attempted using a liquid pre-spotting formulation or semi-solid stick formulation containing a detergent.
Pre-spotting with a detergent formulation alone has been at best only moderately successful at removing organic stains. Addition of an enzyme that is a protease can potentially digest or at least partially digest the protein in the blood or organic stain. However, enzyme containing liquid spot removers have known problems. Separation of the different components of an aqueous spot remover containing an enzyme(s) into different layers or phases (termed phase separation) and a resulting decrease in spot removing capacity is known to occur.
Additionally, since enzymes themselves are proteins, they can digest each other. Further, enzymes must maintain a certain chemical configuration or shape in order to remain active. A change to that configuration which results in inactivation is called denaturation. Heat, unfavorable pH, and other such conditions may result in denaturation or partial denaturation of the enzyme, thus decreasing the shelf-life of the spot remover or at least rendering the spot remover less effective with time. Formulating an effective organic spot remover containing enzymes that remains phase stable and that maintains enzymatic activity has proven difficult. Further, many spot removers contain phosphates and other chemicals that can pollute the environment.
Various patents have proposed ways to stabilize single enzyme type detergent compositions. U.S. Pat. No. 3,819,528 provides an aqueous enzyme composition wherein the enzyme is an amylase. A water soluble calcium salt, and an organic stabilizing agent such as 1,3-propanediol or an aliphatic glycol are illustrated as stabilizers. U.S. Pat. No. 4,287,082 (Tolfo, et al.), incorporated herein by reference, discloses a homogeneous proteolytic enzyme-containing liquid detergent composition containing saturatured fatty acids. U.S. Pat. No. 5,422,030, the disclosure of which is incorporated herein by reference, provides liquid detergents with an aromatic borate ester to inhibit proteolytic enzyme degradation of the enzymes in the composition.
It is an object of the instant invention to provide a liquid spot or pre-spot remover solution containing detergent and at least two enzymes that has enhanced enzymatic stability and sustained organic and blood spot removing capacity.
It is an additional object to provide a blood and organic spot remover that is environmentally friendly and that is biodegradable.
It is a further object of the instant invention to provide a liquid spot or pre-spot remover containing detergent and at least one protease enzyme where the activity of the protease enzyme is at least 80%, and preferably 90% or greater, for at least eight weeks.
It is a still further object of the instant invention to provide a spot or pre-spot remover having an enzyme system comprising at least two enzymes, a protease and an alpha amylase and a detergent that maintains activity or enzymatic stability for at least eight weeks. Enzymatic stability is defined as the ability of an enzyme to maintain its catalytic activity to a designated substrate in order to digest the substrate into shortened components that are more easily washed away in detergent and/or with water. Preferably the spot remover composition as a whole is phase stable and active for at least eight weeks.
It is an additional object of the present invention to provide a blood and organic spot remover that has germicidal activity.
The instant invention is a blood and organic stain remover comprising a protease, an amylase, an enzyme stabilizing system, a nonionic detergent, and water. A method of using the aqueous blood and organic stain remover composition as a germicide is also provided. The composition may be incorporated into a pre-moistened prepackaged wiper that allows the user to remove a blood and organic stain without coming into direct contact with the stain. The packaging folds so that the moistened area of the wiper need not come in contact with the skin of the user. The wiper is especially useful for cleaning clothing and hard surfaces such as for example, tables, chairs, instruments and the like.